Variable capacity pump



vJuly 21, 1936. E. c. LINTHIICUM 2,043,272

VARIABLE CAPAC ITY PUMP Filed NOV. 22, 1932 3 Sheets-Sheet 1 INVENTORY- igifidjm/awv i ATTbRNEY y 1935- E.'C. LINTHICUM 2,048,272

VARIABLE CAPACITY PUMP I NVENTOR imam"? UZfiWW/UU/V ATTORNEY y 1936. E. c. LINTHICUM VARIABLE CAPACITY PUMP Filed Nov. 22, 1932 5 Sheets-Sheet 5 INVENTOR E 1/2227)" 5' Zf/YTfi/GU/W @Q QM ATTORNEY Patented July 21, 1936 UNITED STATES PATENT OFFICE VARIABLE CAPACITY PUMP Everett 0. Linthicum, National City, Calif., as-

signor oi twenty-two and one-half per cent to Lewis S. Murray and twenty-two and onehalf per cent to- John B. Coker, both of San Diego, Calif.

Application November 22, 1932, Serial No. 643,852

My invention .relates to variable capacity pumps, and the objects of my invention are:

First, to provide a pump of this type which has a free or neutral position in which it may rotate without performing its pumping action;

Second, to provide a pump of this type wherein the capacity of the pump may be varied at" of its several pistons, the pistons coming to rest when the pump is in its neutral position;

Fourth, to provide a variable capacity pump.

which is operable on either liquids or air;

Fifth, to provide a novel capacity changing meanswhich is applicable not only to pumps but also to internal combustion engines or the like in cases where variations in the compression ratio is desirable;

Sixth, to provide a pump of this type which is inherently free from vibration, the various forces tendingto balance each other; and

Seventh to provide on the whole a novelly constructed pump of the type which is particularly compact of construction, eflicient in its acpump taken through ll of Fig.2; Fig. 2 is a transverse sectional view thereof taken through 2--2 of Fig. 1; Fig. 3 is a perspective view of the hub forming part of the stroke changing mechanism; Fig. 4--is a similar perspective view of the hub tilting means also forming part of the stroke changing mechanism; Fig. 5 is another transverse sectional view generally through 5-5 of Fig. 1 with parts and portions broken away or shown in elevation to iacilitate the illustration; Fig. 6 is a fragmentary sectional view through 6-6 of Fig. 5 with parts and portions shown in elevation.

Similar characters of reference refer to similar parts and portions throughout the -several views of the drawings. a I I r The pump is provided with a body casing I,

3 Claims. (01. 103-173) which is cylindrical in form with outwardly flanged ends. Each end is closed by an end casing 2. The end casings continue axially from the ends of the body casing I for a short distanceforming cylindrical portions 2a. Near their extremities the cylindrical portions 2a are closed by partitions 2b. Supported from the inner sides of the partitions 2b and extending axially into opposite ends of the casing l are a plurality of cylinders 3. The cylinders are disposed adjacent the cylindrical portions 2a and body casing I and are arranged in axially alined pairs. Five pairs of such cylinders are illustrated but a greater or lesser number may be provided.

At the extremity of one of the end casings there is provided an end wall 20 which covers the partition 2b and is disposedin spaced relation therewith so as to form a chamber 2d occupying the end of the pump. The other end casing is provided with an annular end wall 2e which forms with the corresponding partition 2b an annular chamber 2].

In axial alinement with each of the cylinders 3 the end walls 20 and 2e support intake valve units 4 .each of which includes an intake valve .411 which coactswith a valve seatformed in the 2 support exhaust or discharge valve units 5, one

disposed radially outwardly from each cylinder 3. Each discharge valve unit 5 includes a discharge valve 5a which extends inwardly from the cylindrical wall 2a of the corresponding end casing and coacts with a valve seat formed at the radially outward side of the corresponding cylinder 3, as shown best. in-Figs. l and 5 The valve ia and its valve seat control a port which communicates with the interior of the corresponding cylinder adjacent its head. Around the several valves 50. the cylindrical portions of the end casings 2 are recessed so as to form a space between the end casings and cylinders whereby the discharging fluid may flow into the interior of the-pump.

Between adjacent pairs of cylinders, except at the bottom, thereareprovided large connecting tubes 6 which communicate between the chambers 2d and 2'}.- The chamber 2d is pro-.

vided withan inlet opening 2h, while the bottom of the body casing lis provided with an outlet la. The fluid therefore passes into the chamber 2d and into the body casing I, either directly through-the cylinders connected with the corresponding end casing or through the connecting tubes to the chamber 2! and then through the cylinders connected therewith to the interior of the pump.

The end casing having the chamber 2d supports an axially inwardly extending centrally disposed blind bearing 21', while the other end casingsupports a bearing 2k. This bearing is .pro-

vided with a suitable packing gland 2111.. A drive shaft 1 is supported by the bearings 27' and He and extends outwardly through the packing gland 2m.

Between the bearings the shaft 1 is square in cross-section. A hub 8 is mounted on this portion of the shaft. Said hub has a bore therethrough, designated 8a, the side walls of which bear against the side walls of the square sectioned portion, designated Ia of the shaft I. The remaining walls of the bore 8a diverge from the center of the hub towards the opposite ends, as shown best in Figs. 1 and 3. One of such walls, designated 8b, is spaced from the corresponding side of the shaft throughout. In order to permit tilting or wabbling of the hub with respect to the shaft 1 in the desired manner, there is provided a pin 8 which extends through the square so as to rot te with the shaft 1 but be slidable along its p0 onal or square sectioned portion. From one side of the rack Illa extends an arm lob whichfits between the cutaway portion 8b of the" bore 8a and corresponding side of the shaft, as shown best. in Fig. 1. ture 'of the arm lob with the rack Illa there is formed an integral wedge element lllc. At the i extended end of the arm lob there is formed a removable wedge element "Id. The two wedge elements lllc and Ind engage the curved wall of the cut-away portion 8b so that the hub is caused to tilt or wabble about the axis of the Pin 9. ranged so that the hub ,tilts from a position in which it coincides with that of the shaft in one direction untilits axis is in the desired angular relation with, that of the .shaft.

The circular rack "la is operated by a pinion gear fl mounted on a control shaft 12 which is supported from the body casing I by means of bearings lb. The shaft l2 extends-from the casing and is provided with any suitable arrangement whereby the movement of the control shaft l2 and consequently the tilting of the hub may be manually controlled.

"The hub 8 journals a spider i3 bymeans of a pair of main bearings ll." The spider i8 is pro- "vided with: a plurality of radiating arms In which extend between-themem'bers of each pair of cylinders. Each arm fla is provided at its opposite axial sides with socket members l8b into which fltball portions Iia formed atthe ends of connecting rods 15. The remaining ends of said connecting, rods are also provided with ball portions lib which fit into sockets lia at the inner ends of pistons l8. The pistons l6 fit in the cylinders 8.

In order to prevent rotation of the spider l3 and thereby limit its movement to a tilting one At the junc- The various parts are preferably arwhereby the principal movement of the several arms |8a is reciprocal, two adjacent arms "0 support ball members I! at their adjacent sides which engage opposite sides of a key bar l8. The key bar I8 is.rigidly supported from the body 5 casing I. The several connecting tubes 8 extend between the remaining spaces formed by the arms l3a, as shown best in Fig. 2.

Though I have shown and describeda particular construction, combination and arrangement 10 of parts and portions, I do not wish to be limited to this particular construction, combination and arrangement, but desire to include in the scope of my invention the construction, combination and arrangement substantially as set 15 forth in the appended claims.

Having thus described my invention, what claim as new and desire to secure by Letters Patent is:

1. In a variable capacity pump wherein there 2 are pairs of axially alined cylinders, the several pairs arranged about and parallel with a common axis, a drive shaft disposed along said common axis, and pistons for sai cylinders, the combination with said cylinders, drive shaft and 25 pistons, of means for recipr cating said pistons ously tilting said rotating element with respect to said shaft, a pinion meshing with said gear rack and means independent of said pistons and cylinders for holding said non-rotating element against rotation to minimize side thrust between. said pistons and cylinders consisting of ball members supported by said non-rotating element, and a stationary key bar supported longitudinally with said shaft intermediate said ball members for guiding the same. V

2. In a variable capacity pump wherein there are pairs of axially alined cylinders arranged about and parallel with a common axis, a drive shaft disposed along said common axis, pistons for said cylinders, the combination with said cylinders, drive shaft and pistons of, means for reciprocating said pistons including a hub mem-- ber rotatable with said shaft and tiltable around its median line and positioned at right angles to said shaft, a hub tiltingv member shiftable longituzdinally with said shaft including, an annular gearrack surrounding said shaft and provided with an extended arm member engageable with said hub member for tilting the same, a pinion meshing with said gear rack, a non-mtatable element carried by said rotating element 00 in centered relation and tiltable therewith and surroundingsaid shaft, said non-rotatable element carrying a pair of balls in spaced relation, and a key bar secured longitudinally with said shaft and interposed betweensaid balls for holding said-non' rotatable element against rotation but permitting its tilting movement.

3. In a variable capacity pump wherein there are pairs of axially alined cylinders arranged about and parallel with a common axis; a drive shaft disposed along said common axis, pistons for said cylinders, the combination with said cyl inders, drive shaft and pistons of, means for reciprocating said pistons including ahub membe; rotatable with said shaft and tiltable around its median line and positioned at right angles to said shaft, a hub tilting member shiftable longitudinally with said shaft including, an annular gear rack surrounding said shaft and provided with an extended arm member engageable with said hub member for tilting the same, a non-rotatable element carried by said rotating element in centered relation and tiltable therewith and surrounding said shaft, said nonrotatable element carrying a pair of balls in spaced relation, a key bar secured longitudinally with said shaft and interposed between said balls for holding said non-rotatable element against rotation but permitting its tilting movement, and pinion and control shaft means in operative relation with said annular gear rack for shifting the same.

EVERETT C. LINTHICUM. 

